In ophthalmology, and particularly with vitreous body surgery, specific devices in combination with correspondingly suited microscopes are used, in order to makes possible a contact-free, wide-angle observation of the eye. In particular, with operations on the eye, optical devices are used, with which the surgeon can observe the movements performed with the operating implements, whereby, by the adjustment of the lens in the region between the objective of the microscope and the eye, focusing in different planes is made possible.
Such a device is known, for example, from EP 11 99 591 A1. With this device, the driving movement of a drive motor provided on the microscope can be transferred with the assistance of a flexible drive shaft on a linear gear provided on the device.
Since the devices are used in the direct operating area in the eye, sterilization of the devices, for example, by heating and aerating in autoclaves is of the greatest importance. One disadvantage associated with the device known from EP 11 99 591 A1 is that for transferring of the drive movement, a relatively rigid drive shaft is required. Based on the rigidity of the drive shaft, this can be fixed only inadequately flexibly along suitable attachment points, so that an unwanted contamination of the shaft by contact with non-sterilized objects, for example, the housing of the microscope, can occur. A further disadvantage of the drive by means of a drive shaft is that the device can be pivoted relative to the microscope only within determined limits, since the drive shaft can snap off easily. In addition, the maximum distance between the drive motor and the device is limited by the drive shaft.
An object of the present invention, therefore, starting from this state of the art, is to propose a new, optical device for releasable attachment to a microscope, whose manipulation and hygienic qualities are improved compared with the known devices.